Low dropout linear regulator circuit, power supply chip and electronic equipment

Abstract

A low dropout linear regulator circuit, a power supply chip and an electronic device wherein the low dropout linear regulator circuit comprises: a voltage input terminal for receiving an input voltage; the anti-surge module comprises a bidirectional TVS (Transient Voltage Suppressor) tube, and the anti-surge module is connected with the voltage input end and is used for carrying out voltage stabilization processing on the input voltage and reducing peak burrs of the input voltage; a first electrostatic protector, wherein the first electrostatic protector is connected with the anti-surge module; the linear voltage regulator module comprises an input end and an output end, and the input end of the linear voltage regulator module is connected with the first electrostatic protector; and the voltage output end is connected with the output end of the linear voltage regulator module and is used for providing output voltage, and the anti-surge capability of the power supply chip is remarkably improved on the basis of not increasing the process complexity of the module.

Description

Technical Field

[0001] This invention relates to the field of linear voltage regulators, and more particularly to a low-dropout linear voltage regulator circuit, a power supply chip, and an electronic device. Background Technology

[0002] A low drop-out linear regulator (LDO) is a common voltage regulator that provides a stable output voltage when the power supply voltage or load current changes.

[0003] Low dropout linear regulators are widely used in various electronic devices, such as mobile communication devices, computers, and industrial control systems. In these applications, by selecting and using low dropout linear regulators appropriately, a stable power supply can be provided, thereby ensuring the normal operation of the electronic equipment.

[0004] A surge is a peak voltage or current value that occurs instantaneously and exceeds the stable value; it is a violent pulse that occurs within a fraction of a second. Causes of surges include short circuits, power switching, and lightning strikes. Therefore, surge protection devices are designed in existing technologies to effectively absorb sudden, enormous energy and protect connected equipment from damage.

[0005] However, the surge protection capability of existing low-dropout linear regulator circuits needs further improvement. Summary of the Invention

[0006] The technical problem solved by this invention is to provide a low dropout linear regulator circuit, power chip, and electronic device to improve surge protection capability.

[0007] To address the aforementioned technical problems, this invention provides a linear voltage regulator circuit, comprising: a voltage input terminal for receiving an input voltage; a surge protection module connected to the voltage input terminal for regulating the input voltage and reducing voltage spikes; a first electrostatic discharge (ESD) protection circuit connected to the surge protection module; a linear voltage regulator module including an input terminal and an output terminal, the input terminal of which is connected to the first ESD protection circuit; and a voltage output terminal connected to the output terminal of the linear voltage regulator module for providing an output voltage.

[0008] Optionally, the surge protection module includes a bidirectional TVS diode, which has a first end and a second end. The first end of the bidirectional TVS diode is connected to the voltage input terminal, and the second end of the bidirectional TVS diode is grounded.

[0009] Optionally, the surge protection module further includes: a first capacitor connected in parallel with the bidirectional TVS diode; the first capacitor is used to filter the spikes in the input voltage, so that the energy of the spikes is stored in the first capacitor, and the bidirectional TVS diode is also used to release the energy stored in the first capacitor.

[0010] Optionally, it also includes: a second electrostatic discharge (ESD) protection circuit, which is connected to the output terminal of the linear regulator module and the voltage output terminal.

[0011] Furthermore, the first electrostatic discharge protection circuit includes a first electrostatic discharge protector, and the number of the first electrostatic discharge protectors is one or more; the second electrostatic discharge protection circuit includes a second electrostatic discharge protector, and the number of the second electrostatic discharge protectors is one or more.

[0012] Optionally, the first terminal of the second electrostatic discharge protector is connected to the output terminal of the linear voltage regulator module and the voltage output terminal, and the second terminal of the second electrostatic discharge protector is grounded.

[0013] Optionally, the first and second terminals of the first electrostatic discharge (ESD) protector are connected to the input terminals of the surge protection module and the linear voltage regulator module, and the third terminal of the first ESD protector is grounded.

[0014] Optionally, the linear regulator module includes: an error amplifier, the inverting input of which is connected to a reference voltage terminal; a switching transistor, one of which is connected to the first electrostatic protection circuit, and the other of which is connected to the output voltage terminal; a first resistor and a second resistor, the first end of which is connected to the output voltage terminal, the second end of which is connected to the first end of which is connected to the non-inverting input of the error amplifier, and the second end of which is grounded.

[0015] Accordingly, embodiments of the present invention also provide a power supply chip, the power supply chip including the low dropout linear regulator circuit described above.

[0016] Accordingly, embodiments of the present invention also provide an electronic device, which includes the power chip described above.

[0017] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0018] In the low-dropout linear regulator circuit provided by the present invention, the voltage input terminal is used to receive the input voltage, and the surge protection module is connected to the voltage input terminal to perform voltage regulation on the input voltage, reduce the spikes and glitches of the input voltage, so that the voltage entering the linear regulator module is stable, improves the surge protection capability of the power chip, and does not affect the protection capability of the first electrostatic protection circuit.

[0019] Furthermore, the surge protection module includes a bidirectional TVS diode, which can be integrated into the power chip, thereby significantly improving the surge protection capability of the power chip without increasing the complexity of the module process.

[0020] Furthermore, the surge protection module also includes a first capacitor connected in parallel with the bidirectional TVS diode. The first capacitor filters out spikes in the input voltage, storing the energy of the spikes in the first capacitor. The bidirectional TVS diode also releases the energy stored in the first capacitor. The combination of the first capacitor and the bidirectional TVS diode, while regulating the input voltage, safely releases the energy of spikes, further enhancing the surge protection capability of the power chip. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a low-dropout linear regulator circuit.

[0022] Figure 2 and Figure 3 This is a schematic diagram of the linear voltage regulator circuit in an embodiment of the present invention. Detailed Implementation

[0023] As mentioned in the background section, the surge protection capability of existing low-dropout linear regulator circuits needs further improvement. This paper will now describe and analyze a low-dropout linear regulator circuit.

[0024] Figure 1 This is a schematic diagram of a low-dropout linear regulator circuit.

[0025] Please refer to Figure 1 The low dropout linear regulator circuit includes: voltage input terminal Vin, input terminal electrostatic discharge protector ESD1, linear regulator module LDO, voltage output terminal electrostatic discharge protector ESD2, and voltage output terminal Vout.

[0026] In the aforementioned low-dropout linear regulator circuit, the linear regulator module LDO typically consists of a regulating transistor, comparator resistors R1 and R2, a comparator amplifier, and a reference voltage circuit. When there is a large spike at the voltage input terminal Vin, if the input electrostatic discharge protector ESD1 fails to absorb the surge spike energy, the regulating transistor in the LDO module will be damaged first, causing a short circuit between Vin and Vout, burning out the metal connection. At the same time, the excessively high Vout voltage will burn out the output electrostatic discharge protector ESD2.

[0027] To reduce spike glitches, another possible implementation involves placing a 100nF ceramic capacitor at both the voltage input (Vin) and output (Vout) terminals, which can significantly reduce spike glitches at the Vin input. However, this method increases the complexity of existing module manufacturing processes and is not conducive to reducing the integration density of the power supply chip.

[0028] To address the aforementioned issues, this invention provides a low-dropout linear regulator circuit, a power chip, and an electronic device. A voltage input terminal receives the input voltage, and a surge protection module is connected to the voltage input terminal to regulate the input voltage, reducing voltage spikes and glitches. This ensures a stable voltage entering the linear regulator module, improving the surge protection capability of the power chip without affecting the protection capability of the first electrostatic discharge (ESD) protection circuit.

[0029] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] Figure 2 and Figure 3 This is a low-dropout linear regulator circuit in an embodiment of the present invention.

[0031] Please refer to Figure 2 and Figure 3 The low-dropout linear regulator circuit includes: a voltage input terminal VIN for receiving an input voltage; a surge protection module i, connected to the voltage input terminal VIN, for regulating the input voltage VIN and reducing spikes in the input voltage VIN; a first electrostatic discharge (ESD) protection circuit connected to the surge protection module i; a linear regulator module ii, including an input terminal and an output terminal, the input terminal of the linear regulator module ii being connected to the first ESD protection circuit; and a voltage output terminal VOUT, connected to the output terminal of the linear regulator module ii, for providing an output voltage.

[0032] Here, surge protection module i is used to regulate the input voltage VIN, reduce the spikes in the input voltage VIN, and make the voltage entering the linear regulator module ii stable, thereby improving the surge protection capability of the power chip without affecting the protection capability of the first electrostatic protection circuit.

[0033] In this embodiment, the surge protection module i includes a bidirectional TVS diode, which has a first end and a second end. The first end of the bidirectional TVS diode is connected to the voltage input terminal VIN, and the second end of the bidirectional TVS diode is grounded to VSS.

[0034] Here, a bidirectional TVS diode can be integrated into the power chip, thereby significantly improving the surge protection capability of the power chip without increasing the complexity of the module process.

[0035] It should be further explained that the bidirectional TVS diode (i.e., transient voltage suppressor diode) is a clamping device. When the circuit is working normally, the bidirectional TVS diode is in the cutoff state (high impedance state), which does not affect the normal operation of the linear regulator module. When an abnormal overvoltage occurs in the circuit and reaches its breakdown voltage, it quickly changes from the high impedance state to the low impedance state, providing a low impedance conductive path for the instantaneous current, while clamping the abnormal high voltage within a safe level, thereby protecting the circuit. When the abnormal high voltage disappears, the bidirectional TVS diode returns to the high impedance state, and the circuit continues to work normally, thus stabilizing the voltage entering the linear regulator module.

[0036] In this embodiment, the surge protection module further includes: a first capacitor C, which is connected in parallel with the bidirectional TVS diode; the first capacitor C is used to filter the spikes of the input voltage VIN, so that the energy of the spikes is stored in the first capacitor C, and the bidirectional TVS diode is also used to release the energy stored in the first capacitor C.

[0037] Here, the combination of the first capacitor C and the bidirectional TVS diode not only stabilizes the input voltage VIN, but also safely releases the energy of spikes, further increasing the surge protection capability of the power chip.

[0038] In this embodiment, the low-dropout linear regulator circuit further includes a second electrostatic discharge (ESD) protection circuit, which is connected to the output terminal of the linear regulator module ii and the voltage output terminal VOUT.

[0039] Specifically, the second electrostatic discharge protection circuit includes a second electrostatic discharge protector ESD2, and the number of the second electrostatic discharge protector is one or more electrostatic discharge protectors.

[0040] More specifically, the first terminal of the second electrostatic discharge protector ESD2 is connected to the output terminal of the linear regulator module ii and the voltage output terminal VOUT, and the second terminal of the second electrostatic discharge protector ESD2 is grounded to VSS.

[0041] In this embodiment, the first electrostatic protection circuit includes a first electrostatic protector, and the number of the first electrostatic protectors is one or more.

[0042] In this embodiment, the first and second terminals of the first electrostatic discharge protector ESD1 are connected to the input terminals of the surge protection module i and the linear voltage regulator module ii, and the third terminal of the first electrostatic discharge protector ESD1 is grounded to VSS.

[0043] Specifically, the first electrostatic discharge protector ESD1 has a PNP device structure, with its third terminal being the collector of the PNP device, and one of the emitter and base of the PNP device being its first terminal and the other being its second terminal.

[0044] In this embodiment, Figure 3 The specific circuit structure of the linear regulator module is shown, including: an error amplifier, the inverting input of which is connected to a reference voltage terminal Vref; a switching transistor M, one of its source or drain connected to the first electrostatic protection circuit, and the other source or drain connected to the output voltage terminal VOUT; a first resistor R1 and a second resistor R2, the first end of which is connected to the output voltage terminal VOUT, the second end of which is connected to the first end of which is connected to the first end of which is connected to the non-inverting input of the error amplifier ERR AMP, and the second end of which is grounded to VSS. In other embodiments, the linear regulator module may have other circuit structures.

[0045] In this embodiment, one of the source or drain of the switching transistor M is connected to the first electrostatic discharge protector ESD1.

[0046] Here, the power supply chip formed using the low dropout linear regulator circuit described above will be used to illustrate its surge protection capability through aging test data.

[0047] Aging conditions: Vin = 21V, Io = 3A, Fsw = 380KHZ, T = 85℃, where Vin is the input voltage (aging voltage) provided to the voltage input terminal VIN, and the peak spike of the aging voltage reaches 8V, Io is the input current of the voltage input terminal, Fsw is the operating frequency, and T is the operating temperature.

[0048] Under the aforementioned aging conditions, power chips formed using existing low-dropout linear regulator circuits fail the aging test. However, by adding the surge protection module to the existing low-dropout linear regulator circuit, i.e., using the low-dropout linear regulator circuit of this embodiment, the power chip passes the aging test. Further increasing the aging voltage reveals that the linear regulator circuit can withstand aging voltages above 23V, improving the surge protection capability of the power chip.

[0049] Accordingly, the present invention also provides a power supply chip, which includes the low dropout linear regulator circuit described above.

[0050] Here, the low dropout linear regulator circuit described above can be packaged inside the power chip, which significantly improves the surge protection capability of the power chip while further reducing the area of ​​the power chip and lowering the module process complexity.

[0051] Furthermore, the surge protection module also includes a first capacitor, which is connected in parallel with the bidirectional TVS diode. The first capacitor can adopt a structure such as a MIM capacitor (Metal-Insulator-Metal) or a MOM capacitor (Metal-Oxide-Metal). It can be formed on the same substrate using front-end and back-end processes, respectively, to create a stacked structure of the bidirectional TVS diode and the first capacitor, which further facilitates improving the chip's integration density.

[0052] Accordingly, the present invention also provides an electronic device, which includes the power chip described above.

[0053] The electronic device may include mobile communication devices, computers, and industrial control systems.

[0054] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A low-dropout linear regulator circuit, characterized in that, include: Voltage input terminal, used to receive input voltage; A surge protection module is connected to the voltage input terminal and is used to regulate the input voltage and reduce voltage spikes. A first electrostatic discharge protection circuit is connected to the surge protection module. A linear voltage regulator module, the linear voltage regulator module including an input terminal and an output terminal, the input terminal of the linear voltage regulator module being connected to the first electrostatic protection circuit; The voltage output terminal is connected to the output terminal of the linear regulator module to provide the output voltage.

2. The low-dropout linear regulator circuit as described in claim 1, characterized in that, The surge protection module includes a bidirectional TVS diode, which has a first end and a second end. The first end of the bidirectional TVS diode is connected to the voltage input terminal, and the second end of the bidirectional TVS diode is grounded.

3. The low-dropout linear regulator circuit as described in claim 2, characterized in that, The surge protection module further includes: a first capacitor, which is connected in parallel with the bidirectional TVS diode; the first capacitor is used to filter the spikes in the input voltage, so that the energy of the spikes is stored in the first capacitor, and the bidirectional TVS diode is also used to release the energy stored in the first capacitor.

4. The low-dropout linear regulator circuit as described in claim 1, characterized in that, Also includes: The second electrostatic discharge (ESD) protection circuit is connected to the output terminal of the linear regulator module and the voltage output terminal.

5. The low-dropout linear regulator circuit as described in claim 4, characterized in that, The first electrostatic discharge (ESD) protection circuit includes a first ESD protector, and the number of the first ESD protectors is one or more; the second ESD protection circuit includes a second ESD protector, and the number of the second ESD protectors is one or more.

6. The low-dropout linear regulator circuit as described in claim 5, characterized in that, The first terminal of the second electrostatic discharge protector is connected to the output terminal of the linear voltage regulator module and the voltage output terminal, and the second terminal of the second electrostatic discharge protector is grounded.

7. The low-dropout linear regulator circuit as described in claim 5, characterized in that, The first and second terminals of the first electrostatic discharge (ESD) protector are connected to the input terminals of the surge protection module and the linear voltage regulator module, and the third terminal of the first ESD protector is grounded.

8. The low-dropout linear regulator circuit as described in claim 1, characterized in that, The linear regulator module includes: an error amplifier, the inverting input of which is connected to a reference voltage terminal; a switching transistor, one of which is connected to the first electrostatic protection circuit, and the other of which is connected to the output voltage terminal; a first resistor and a second resistor, the first end of which is connected to the output voltage terminal, the second end of which is connected to the first end of the second resistor and the non-inverting input of the error amplifier, and the second end of the second resistor being grounded.

9. A power supply chip, characterized in that, The power chip includes a low-dropout linear regulator circuit according to any one of claims 1 to 8.

10. An electronic device, characterized in that, The electronic device includes the power chip as described in claim 9.

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